1. Field of the Invention
The invention relates to an anisotropically conducting adhesive with particles dispersed in a thermoplastic base material and to a process for producing an anisotropically conducting adhesive.
2. Description of the Related Art
Anisotropically conducting adhesives are known. In a base material, for instance a thermoplastic base material, they have finely dispersed conductive particles. The conductive particles are dispersed in the form of particulate powder in the base material. The anisotropically conducting adhesives are in sheet form, for instance, and are suited for electrically conductively gluing together two contacts, for instance two conductor tracks. The tracks are pressed under pressure and temperature action onto the opposed sides of the adhesive, so that the base material deformed and the conductive particles distributed in it establish an electrically conductive connection between the applied tracks. The base material performs an adhesive action between the parts having the conductor tracks that are to be glued together.
It becomes clear that the resolution of the anisotropically conducting adhesive, that is, the minimum possible distance between two adjacent electrically conductive connections, depends on the structure of the dispersed electrically conductive particles. In order that the conductive particles will enable the electrically conductive connection in only one direction, they must be spaced apart sufficiently from one another so that an undesired isotropically electrically conductive connection is avoided. This can happen for instance from accidental coagulation, or in other words clumping together of the electrically conductive particles in the base material. As a result, the known anisotropically conducting adhesives can be used only for contacting contacts that are located relatively far apart from one another, because otherwise an adequately high contact reliability is not achieved.